error[E0277]: the trait bound `T: MyDisplay` is not satisfied
  --> $DIR/issue-65774-1.rs:10:33
   |
LL |     type MpuConfig: MyDisplay = T;
   |                                 ^ the trait `MyDisplay` is not implemented for `T`
   |
   = help: the trait `MyDisplay` is implemented for `&'a mut T`
note: required by a bound in `MPU::MpuConfig`
  --> $DIR/issue-65774-1.rs:10:21
   |
LL |     type MpuConfig: MyDisplay = T;
   |                     ^^^^^^^^^ required by this bound in `MPU::MpuConfig`

error[E0277]: the trait bound `T: MyDisplay` is not satisfied
  --> $DIR/issue-65774-1.rs:44:76
   |
LL |         let closure = |config: &mut <S as MPU>::MpuConfig| writer.my_write(&config);
   |                                                                            ^^^^^^^ the trait `MyDisplay` is not implemented for `T`
   |
   = help: the trait `MyDisplay` is implemented for `&'a mut T`
note: required for `&mut T` to implement `MyDisplay`
  --> $DIR/issue-65774-1.rs:5:24
   |
LL | impl<'a, T: MyDisplay> MyDisplay for &'a mut T { }
   |                        ^^^^^^^^^     ^^^^^^^^^
   = note: required for the cast from `&mut T` to the object type `dyn MyDisplay`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0277`.